Background: Effect of asthma on dentoalveolar morphology and oral health unstudied enough and previous studies did not focus on asthmatic children in particular but examined attendant variables with asthma. Aim:Toevaluate effect of asthma on dentoalveolar morphology as change in dental arch width, dental arch length and palatal depth, anddental deformities as dental caries, gingivitis, and dental erosion. Materials and methods: Study conducted on 50 asthmatic children age range from 7-12 years from ACIRU^[1] compared with50 non-asthmatic children by dental cast analysis for upper inter canine width( UICW), lower inter canine width(LICW), upper intermolar width(UIMW), lower inter molar width(LIMW), upper arch length(UAL), lower arch length(LAL),and palatal depth(PD). In addition intraoral examination for dental caries, gingivitis, dental erosion. Results: Children with asthma showed high mean values in upper inter canine width, arch length, and palatal depth. Moreover, lower inter canine width, and inter molar width, when compared with mean value of non-asthmatic children in both gender. While upper inter molar width of asthmatic children had less mean values when compared with mean value of non-asthmatic children. The significance observed in lower inter molar width and lower arch length. On the other hand, asthmatic children had high mean values of dental caries, gingivitis, dental erosion with no significant. Conclusions:Asthma effect on dental arch dimensions and effect on incidence of dental caries, gingivitis, and dental erosion.